6 Type Model for ObjectTypes and VariableTypes ToC Previous Next

6.4 Instances of ObjectTypes and VariableTypes ToC Previous Next

6.4.1 Overview ToC Previous Next

Any Instance of a TypeDefinitionNode will be the root of a hierarchy which mirrors the InstanceDeclarationHierarchy for the TypeDefinitionNode. Each Node in the hierarchy of the Instance will have a BrowsePath which may be the same as the BrowsePath for one of the InstanceDeclarations in the hierarchy of the TypeDefinitionNode. The InstanceDeclaration with the same BrowsePath is called the InstanceDeclaration for the Node. If a Node has an InstanceDeclaration then it shall have the same BrowseName and NodeClass as the InstanceDeclaration and, in cases of Variables and Objects, the same TypeDefinitionNode or a subtype of it.

Instances may reference several Nodes with the same BrowsePath. Clients that need to distinguish between the Nodes based on the InstanceDeclarationHierarchy and the Nodes that are not based on the InstanceDeclarationHierarchy can accomplish this using the TranslateBrowsePathsToNodeIds service defined in OPC 10000-4.

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